March 25 marks the return of Supernatural but there's another important date fans should take note of on their calendars. According to Entertainment Weekly's Michael Ausiello, the show's 100th episode, entitled "Point of No Return," will air on April 15 and will feature a lot of shocking twists.

SPOILER WARNING: Details about the milestone episode are revealed after the jump!

As we reported previously, psychic Pamela Barnes (Traci Dinwiddie) will be resurfacing in the 16th episode called "Dark Side of the Moon." But she's not the only one returning on Supernatural this season. Though exec producer Sera Gamble won't say who else is coming back, she does hint that several characters whom we've never thought we'd see again will return.

We've barely scratched the surface, though. The 100th episode will not only serve as an important series landmark, but it will also serve as a defining moment for Dean (Jensen Ackles). "We definitely kept in mind that this was [an important] episode. We wanted to deliver something with real scope; it's about the Archangel Michael. Crises will come to a head for Dean and Castiel [Misha Collins]," exec producer Sera Gamble reveals.

But the most important and controversial scoop about the milestone episode is this: "A very important character will sacrifice themselves in a suicide mission," reveals Gamble, who is poised to take over Supernatural once Eric Kripke steps down as showrunner for season 6. Care to venture a guess?